Change your radiator hoses

Keep your bike’s cooling system in tip-top condition

Buy the right bits 1

Use either original parts, or branded hoses from a UK supplier. Either option will offer you consumer protection and technical support. Check that the kit contains the correct hoses for your bike; they should have a pre-formed shape which matches the originals. Offer them up for comparison and identify which hose goes where before you take off the old hoses.

Undo the clips 2

Many original clips are of the crosshead type and can become corroded, so spray with a little maintenance fluid. Or, if you have a quarter-inch drive kit, it is often better to use the hand driver and a socket. The most common sizes are 6mm and 7mm. These single-hex type sockets will give a more positive and stronger feel than a screwdriver.

Get ready to catch the coolant 3

Remove any panels or fairings to gain access to the hoses. In the case of our Suzuki GSX-R1000 K3 it needs the fairing lowers removed and the tank tilted up. Remove the top of the radiator cap and work out where to drain the coolant from (usually from the lowest point in the system). Remove the hose from the low end and drain the coolant into a bowl.

Gently does it 4

When both ends of the clips have been loosened, gently twist the hose. It should break its seal, which will allow it to be removed. Hoses may be reluctant to come free (especially if they are the originals and have been in place for years). Your radiator is easily damaged, so take your time to ease the hose off rather than just giving it a tug.

Lift the edge with a screwdriver 5

A hard-to-remove hose can be eased off by gently inserting a thin, flat-bladed screwdriver between the pipe and the hose while also dowsing it with maintenance spray. Work the fluid around the pipe, and it will eventually yield. Once again, take care not to damage anything.

Use genuine clips 7

Replace the old clips with new items. If you’re not using the original clip, then make sure that the replacements are for automotive use and carry a British standard kite mark. Low quality or non-kite-marked clips cannot be relied upon and may fail, leading to serious and potentially dangerous coolant leaks. Bargain clips are a false economy.

Tighten the new hoses 9

Fit the new hoses one at a time. To help them slide on, use your finger to wet the inside of the hose. Next, check the hose is in the correct position and then tighten it up so that the clip just squishes the hose. Ideally, this should be done using a hand drive quarter-inch socket which will give you more control than a screwdriver.

Remove any corrosion 6

Clean the area where the hose is to be fitted with brake or contact cleaner because it is common for corrosion to build up where the old hose was fitted. Use a Scotchbrite pad to remove stubborn bits and take the time to make sure the area is completely clean.

Replace the sleeving 8

Some hoses are sleeved to protect them from chafing or from damage from hot engine parts. Take a note of where the sleeving fits and remember to remove it from the old hose and re-fit it on the new hose so that it sits in exactly the same place. It’s sometimes worth taking pictures of the hoses while still in situ so you can see where the sleeve goes. ‘Always wear protective gloves when dealing with toxic coolant’ When all the hoses are fitted, replace the coolant in the radiator by following the specific instructions in your manual for bleeding the system. Run the engine up to temperature, and then check all the hoses for leaks. It is important to check this, as leaking coolant is potentially very dangerous. With everything performing as it should, replace the bodywork.